Hub Motor Gear Train Layout for High-Torque Lightweight Vehicles

The patent employs a planetary gear system where smaller planetary gears are nested around a central sun gear, all contained within a compact housing. This nesting arrangement allows multiple gears to occupy the same radial space, enabling a large effective gear ratio without increasing the overall device footprint or complexity significantly. The planetary gears work together in a coordinated manner to achieve the desired torque multiplication.

The patent divides the torque generation function into two separate components: a standard-sized electric motor and a planetary gear transmission system. Instead of using one large motor, the system segments the function by using a smaller motor to drive a gear system that multiplies torque. This segmentation allows the use of a lighter, less expensive motor while achieving the same output torque through mechanical advantage from the gear system.

The patent uses a standard off-the-shelf electric motor that can be applied to multiple vehicle applications, rather than a custom-designed motor. This universal component approach reduces manufacturing costs and simplifies production. The planetary gear system serves as a multi-functional element that simultaneously provides torque multiplication, speed reduction, and compact packaging, achieving multiple objectives with a single subsystem.